Gun mount for aeroplanes



Feb. 9, 1932. A. ALLAN ET AL (':I'rUN MOUNT lFOR EROPLANES Filed Jan. 9, 1931 far Patented Feb. 9, 1932 .Maz

ALEXANDER ALLAN, oF MIDDLETOWN, AND WILLIAM HARRISON INNES, OF NEWPORT,

` Y Y RHODE ISLAND" GUN lvroUNfr ron. AEROPLANES This invention relates to an improved gunmount particularly for swiftly moving car-v ri'ers, such as aeroplanes, which create considerable windage by their motion. On an '5 aeroplane, for example, it is desirable to mount a gun so that it can be trained in various Vdirections relative to the heading of the aeroplane and on either side thereof. To this end the gun may be swivelly mounted on a support which, in turn, is rotatable about a vertical axis through the center line of the fuselage, the portion of the support carrying the gun being oifset from the axis so as to present the gun on either side of the 15 aeroplane with the gunner behind it in operating position. With a gun-mounting of this type, lateral pressure Of the wind on the gun itself is a disturbing factor tending to rotate the support on its axis when -l the gun is trained broadside or in any direction other than fore ,and aft. This interferes with the free action of the gun mount which' is essential for the effective operation of the gun. The drag of the gun on one side or the other of the aeroplane, unless suitably counteracted, seriously affects the steering of the aeroplane itself. This is especially tr'uerof guns which are provided with a shield for the protection of the gunner. VAccording to the invention counteracting means such as a vane is mounted on a bracket on the rim of the gun-mount opposite to the gun to present a resisting surface'to the wind to offset the pressure on the itself.

Y 'As different makes of machine guns present dilferent resisting surfaces to wind pressure, the balancing vane may be.Y made ad! justable so as to balance anymake of machine gun. v Y l For amore Complete understanding of the invention, includingk additional advantageous features, reference may be hadV to the descriptionthereof which follows and to the drawings, of which, Y

Figure 1 is a perspective view of an embodiment of the invention as it mightap; pear installed in an aeroplane.

Y Figure 2 is a side elevation of a gun-mount ,50 embodying the invention, portions being brosuitably spaced.' The top of the post 12may vhave a circular plate 14 to which is rigidly `rests on ball hearings carried by a supportlien away to show the inner parts in secion.

Figure 3 is a sectional detail of a portion of the mechanismk shown in Figure 2.

Figure L is a section on the line4-4 of Figure 3.

Figure 5 is a section on the line 5 5 of Figure 2.

Figure 6 is an elevationshowing a modi-4 fied mounting for a vane. .l

The invention may be embodied in a r0- tatable mount 10 which has a central cylindrical tube 11 surrounding and bearing on a fixed post 12, the latter 'being securely mounted on the framework of the' aeroplane. The mount 1() also includes diametrically opposed portions laterally offset from the central tube 11 to support a gun and a vane respectively. The mount 10 as a whole may be in the form of a cup, as shown, the gun and vane beingrsupported on opposite portions of its rim. The mount 10 may be nested within a larger cupeshaped receptacle 13, from the walls and bottom of which'it kis attached an inner cup-shaped member 15 which serves asa cockpit forthe operator of thegun. The cockpit 15 has a central hollow column 16, the top of which is secured directly to the plate 14. I The column 16 may support a suitable seat 17 projecting from a ring 18 which encircles the tubular member 16. The seat ring 18 preferably ing ring 2O which is adjustably fixed on the column 16 by a set screw or'otherwise. A retaining ring 19 may also be mounted on the column 16 just above the seat ring 18.

It is desirable that the 'gun-mount" 10 `be capable of free rotation so asto facilitate the training ofthe gun in any desired direction. To this end suitable roller bearings or ball bea-rings 22 may be provided between the lowy er portion of the post 12 and the tubular portion 11 of the mount,A and a'second ball bearing 23 maybe employed between the upper kportion of the post 12'andthetube 11. A third ball bearing 211 may also he provided be,- y tween the lower portion ofV the tube 11 and the "W Column 16. These bearings take the lateral thrusts arising from any tiltingof the aeroplane and permit the ready rotation of the mount 10 when the aeroplane is in any position whatever. To retain. the ball bearings 23 in place, a suitable cone, with check nuts to permit adjustment, may be mounted on the post 12. Fixed to the upper rim of the mount 10 is a swivel standard 30 which carries a machinegun 31 or other equivalent weapon. In order to counterbalance the wind pressure on the gun 31, a vane may be mounted on the rim of the mount 10 at a point diametrically opposite the gun 31. A single plate isA found to be unsuitable for this purpose since .it is usually presented at an angle tothe direct-ion of motionvof the aeroplane. It thus 'acts as a rudder, causing a powerful lateral draft and seriously interfering` `with the guidance of the aeroplane. According to` the present invention, a vane is provided which offers the desired resistancewith the minimum resultant lateral draft. To this end a post 32 may be outwardly offset from therim of the mount 10 as by a bracket 33 so that the vane will not interfere with the operator. Swivelly mounted on the post 32 is a vane consisting of a bearing sleeve 34 fitted Vin Athe post, and a pair of vertical plates 36 and 37 each swivelly mounted along one edge on the sleeve 34 and adjustable toward and from each other. Thus the vane, as a whole, swings onthe post 32 as an axis, the post as illustrated being at the intersection of the planes of the plates 36 and 37. In order to adjust the wind resistance of the vane, means is provided for holding the two plates in adjusted lrelative angular position. To this end a supporting bar 38 is tixedto and projects laterally from the bearing sleeve 34, this bar carrying a ratchet quadrant 40, `the teeth ofv which are engaged by a detent'41 mounted on a hand lever 42 which ispivoted as at 43 at the center of curvature of the ratchet quadrant 40.* The lever 42 is provided with a pair of ears 44, `45 which'l are connected respectively by links 46, 47 to similar ears 48, 49 on the .plates 36 and 3'?. lIt is apparent that when the lever 42 is Vswung toward the post 32,v this motion will cause the plates3`6, 37 to swing apart formingv a larger angle between them.

This increases the wind 'resistanceof the vane,

since the vane as a whole is free to swing away yfrom the wind and thus'always heads into the wind.l j

vThe vane as a' whole need notbe pivoted at the intersection of the plates, but may be pivoted elsewhere as shown, for example, in Figure 6. In this form, the-post 32 may project through the bar 38 at a point laterally spaced from the line of intersection of the-plates. In such case the bar 38 may beprovide'd with an extension 39 extendin'gupthrough the hinge membersv of the`plates'36 and 37, and 'then mounted on `the inside wall of the receptacle 13. The rail v50 is provided with ratchet teeth 51 along its upper edge and similar teeth 52 along its lower edge. Engaging these teeth, respectively, are aV pairof pawls 537and 54, these pawls being rockably mountedon pins 55 and jprojecting outwardly from the cylindrical' wall of the mount 10. A bellcrank 60. mayfbeprovided to disengage the pawls from their ratchets when it is desired to swingthe gun-mount 10 toa different angular position. -Twoarmsof the bell crank 60 are provided with pins 61, 62 which enter respectively slots 63 and 64 in the pawls 53 and 54. These slots are arrangedin such a way shown in Figure 4,.that when the arms of the bell-crank 60 are swung'in one directiomthe pawls 53 and 54 are held in engagement-with the teeth of their respective ratchets. When the bell-crank 60 is swung in the opposite di-'- rection, the pawls 53and 54 are Vmoved clear of their ratchets. The third arm 65 of the bell-crank may be connected to a rod (i6-which is movable downwardly vby pressure on a knob 67 at its upper end to release the pawls 53 and 54 from their ratchets. The operating knob 67 is preferably located to the left ofthe gun so as to be-easily operable by the left hand of the gunner while his right hand is being used inthe operation 'of the gun. The rod 66 is l normally held-in its uppermost position as by a spring 68 which is compressed between the knob 67 and the upper rim ofthe gunmount 10 through ywhich the rod passes.

The arrangement of three concentric cups Tl affords considerable protection both to the gunner and to the bearings of the mount.

The latter are contained within a narrow col- 1 umn ona spindle, and, do not offer much of a target. The bearings arefurthermore-protected byfive walls from: lateral vlire so that it would be diiiicult for an enemy .to put the mount out of. commission. The protection `of the bearings is. of.A vital importance `-asn in aeroplane fighting, the gun Ymust frequent- 7:'

quickly beswung from onesidevtothe ly and other.

that many modifications `and Vch'anges'can be ymade in the specific embodiment ofthe invenrections from said axis, a gun support on 'one of said portions, anda vane on the opposite It'vwill be evidentto one "skilled inthe 'arti portion, said vane including a pair of surfaces making an angle with each other and pivotally supported at or near the apex of said angle.

5 2. Mechanism of the class described comprising a member pivotally supported to turn on a vertical axis, said member having portions extending laterally in opposite directions from said axis, a gun-support on one of said portions, and a vane on the opposite portion, said vane including a pair of surfaces making an angle with each other and pivotally supported at theV apex of said angle, and means between said surfaces for holding .them in adjustable angular relation to each other.

3. Mechanism of the class describedcomprising a cup-shaped receptacle having a central tubular member, a xed supporting post extending upwardly through said member,

bearings on said post for supporting said receptacle, al gun-supporting bracket mounted on the rim of said receptacle, and a vane mounted on said rim diametrically opposite to said bracket.

4. Mechanism of the class described comprsing a cup-shaped receptacle having a central tubular member, a fixed supporting post extending upwardly through said member,

bearings on the sides of said post for supporting said receptacle, a cup-shaped cockpit nested in said receptacle and spaced therefrom, said cock-pit having a central tube surroundingsaidtubular member and secured to the upper end of said post, a gun-supporting bracket mounted on the rim of said receptacle, and means on said rim opposite said bracket for counteracting the wind pressure on a gun carried by said bracket.

5. Mechanism of the class described comprising a cup-shaped container, a central post iixed therein, a member pivotally sulp- `ported on said post to revolve around tie axis thereof, said member having portions extending laterally in opposite directions from said axis, a gun-support on one of said portions, a wind resistance vane on the other Said portion, and means for releasably locking said container and member against relative rotation. y

In testimony whereof we have axed our signatures.

ALEXANDER ALLAN.

WILLIAM HARRISON INNE S. 

